1. Field of the Invention
The present invention relates to a print control program, a print control method and an information processing apparatus. More particularly, the present invention relates to a print control process performed by a system that includes an information processing apparatus, such as a personal computer, and a printing apparatus, such as a printer, for creating and printing images that include tint block images for putting brakes on use of a duplicate.
2. Description of the Related Arts
Conventionally, for inhibiting or restraining copying of forms and certificates of residence, the contents of such documents can be printed on a print medium, on which special print is given, is called forgery inhibiting media. The forgery inhibiting medium is given characters such as “COPY” and the like, which human beings are difficult to visually distinguish when the medium is in an original but are visualized when the medium is subjected to copying by a copy machine. Thus, the forgery inhibiting medium has an effect that makes a person who performs copying have a hesitation in use of duplicates. Also, the forgery inhibiting medium has an effect that restrains or inhibits copying itself because the forms or the like is printed on the forgery inhibiting medium.
However, when compared with common-use print media, the forgery inhibiting media are expensive. Further, since when copying documents, only those characters will appear that were designated at the time of manufacture of the forgery inhibiting media, limitations are imposed on their use, i.e., the use of the forgery inhibiting media is not very flexible.
On the other hand, amid various types of contents are often digitized, also the contents of forms and certificates of residence are digitized. However, the digitization of handling and usage of such digitized forms and certificates of residence are still in a period of transition. In many cases, therefore, contents of digital data generated by use of a computer are outputted on a paper so as to be used.
While taking this situation into account, a technique has been proposed whereby a computer and a printer can be employed to create a forgery inhibiting sheet that conventionally would be prepared in advance using plate making (Japanese Patent Application Laid-open No. 2001-197297). According to this technique, when content data created by a computer are printed, print data is created by superimposing image data called a tint block on the content data, and print out is performed based on the print data. The tint block is also called a forgery pattern. That is, the tint block image (also referred to as “copy-forgery-inhibited pattern image”) on an original (i.e., on printed matter output by a printer) appears to human eyes to be only a simple pattern or a mere background color, but is visualized as predetermined characters or a predetermined image when the original is duplicated. Thus, as described above, an original on which the tint block image is printed provides the same inhibiting function as the above described forgery inhibition sheet.
Since tint block images which are superimposed on the content data prepared by a computer, can be output using common-use print media, a cost advantage is realized that is not available when the forgery prevention media prepared in advance are employed. Further, since the tint block image can be created when the content data are printed, not only the color of the tint block image but also characters that become visible when an original is copied can be arbitrarily designated. In addition, information inherent to a printing apparatus, such as the date and time output and the name of the printer, can be used as the tint block image.
As described above, when an original is duplicated, predetermined characters that can not be visually identified before duplication become visible as the tint block image. This visualization of the tint block image can restrain the use of the duplicate, and can allow the duplicate to be easily recognized in a visual way that the printed matter is a copy, i.e., is not an original. In order for this effect to be obtained, basically, the tint block image includes two areas: an area wherein, as a result of duplication, an image is found (appears) on a duplicate; and an area wherein an image disappears or an image density becomes light compared with the image found in the other area. These two areas have almost the same density when these areas are printed, and macroscopically, the printed matter including these two areas can not be visually recognized that characters or the like are hidden that become visible on a duplicate. However, microscopically, e.g., at the printed dot level, the areas have different characteristics, as will be described below.
Hereinafter, for the sake of convenience, an image that appears in a copy is called a “latent-image” and an image that disappears or becomes light in a copy is called a “background image”. A tint block image basically consists of the latent-image and the background image. It should be noted that as a user interface term a latent-image may be called a foreground.
The form of a tint block image is not limited to the one described above, and may take any form, such as a character string “COPY”, a logo or a pattern, that appears (becomes visible) in a duplicate so as to be identified by a human being. That is, also in the case that a character string “COPY” of an outline state appears in a duplicate, its purpose as a tint block image can be achieved. In this case, the character string “COPY” is prepared as a background image.
For a dot printer, such as an electro-photographic printer or an ink jet printer, an area wherein an image is fond in a duplicate copy (in a latent-image portion or a foreground portion) is formed with a concentrated set of dots. An area (a background portion) wherein the image in the duplicate copy disappears, or the image is reproduced at a density lower than that in the other area wherein the image appears, is formed using a dispersed set of dots. Then, when the tint block image is printed, the densities in these areas are adjusted so they are almost equal and the overall density of the tint block image is substantially uniform.
FIG. 15 is a diagram showing the two areas. As shown in FIG. 15, the tint block image is formed of the background portion, wherein dots are putted dispersedly, and the latent-image portion, wherein concentrated dots are putted. These two areas can respectively be generated by employing different halftone dot processes or different dithering processes. In case of creating the tint block image by performing the halftone dot process, the halftone dot process for a small line number is appropriate for the latent-image portion, while the halftone dot process for a large line number is appropriate for the background portion. In the case of creating the tint block image by performing a dither process, the dithering process employing a dot concentration dither matrix is appropriate for the latent-image portion, while the dithering process employing a dot dispersion dither matrix is appropriate for the background portion.
For a copying machine that copies a tint block image that is printed in the above described manner, there is a limiting point to a reproduction capability that depends either on an input resolution that can read a minute dot of a document image, or on an output resolution that can reproduce a minute dot. Therefore, a dot of the background portion of the tint block image can be formed smaller than the limiting point of the dot that the copier can reproduce, and a dot of the latent-image portion can be formed larger than the limiting point. As a result, the portion of the tint block image formed using a group of large dots is reproduced in a duplicate, and the portion formed using a group of small dots is not reproduced (is not found) in the duplicate. Thus, the latent-image can be visualized and the background can be disappeared. Further, even if in a duplicate dispersed minute dots do not completely disappear, so long as their density is low, compared with the density of the groups of concentrated dots, the visibility of the latent-image will be enhanced.
FIGS. 16A and 16B are diagrams showing the visualization of a latent-image. In FIG. 16A, the state wherein a tint block image has been printed is shown, and in FIG. 16B, a duplicate obtained when the original image, shown in FIG. 16A, is copied by a copying machine is shown. By referring to FIGS. 16A and 16B, it can be understood that the latent-image, formed of groups of concentrated dots, appears, and that the background, formed of dispersed dots, disappears.
In a system wherein a printing apparatus, such as a printer, is connected to an information processing apparatus, such as a personal computer, to perform printing, generally, the personal computer employs a program that includes a function for the issue of printing instructions to the printer. The computer also employs a program (a printer driver) that, for printing, serves as an intermediator between an application and a specific printer and that provides more specified printing control. For the system configuration, it is preferable that the above described operation of the computer, for creating a tint block image, be performed by a printer driver, and recently, many printer drivers have become available that include a tint block image printing function.
Whereas printer drivers on CD-ROM media are ordinarily provided users as printer accessories or are distributed at no cost via the Internet, printer drivers having incorporated tint block printing functions, as value-added add-ins, or library modules that provide tint block printing functions, and are separately installed, are often sold separately as fare-paying software products.
Fare-paying software products, including the printing-relevant products described above, tend to be shunned by users, and accordingly, the sale of such products is languishing. It has therefore been proposed that, for promoting the sales, parties who produce and sell software products provide the software to users without cost for limited trial periods, to permit the users to employ and evaluate software before purchasing it. For example, when a user has employed a software product for a limited trial period and decides, as a result, to purchase it, the user need only purchase a license to continue to use the software following the expiration of the trial period. On the other hand, if a license is not purchased after the expiration of the trial period, continuing use of the software can be inhibited by an incorporated timing process (Japanese Patent Application Laid-open No. 2003-5974).
However, for an example of a printer driver which includes a tint block printing function, when the purchase of a license does not occur before the expiration of a trial period, the execution of the above described process that merely inhibits the use of the software may be improper.
For example, when printing using such a printer driver is disabled once a trial period has expired, it constitutes a great inconvenience for a user who desires only to perform normal printing. That is, of the users who employ of these printer drivers for printing, there will be some who are not particularly aware they have a tint block printing function or know little about it. For these users, it may be incomprehensible that all printing is disabled once the trial period has elapsed. Especially, while taking into account the fact that generally a common printer driver not having a value-added function, such as the tint block printing function is provided at no cost, users may not fully understand why printing has been disabled. Furthermore, when all printing is inhibited upon the expiration of the trial period, the printing operation is not properly done, e.g., scheduled printing can not be performed.
To resolve these shortcomings, it is possible inhibit only the use of the tint block printing function when a trial period has elapsed. This is preferable, because it is not caused that a user will have incomprehensible feel and the printing operation will not be properly done. Further, in the case that after the trial period has expired a user who continually employs the software desires to use the tint block printing function, it is preferable for the user and the maker that, even though the tint block printing is not normally executed, the user can experience some of the effects associated with the tint block printing function. This is because such a user experience can promote the sale of a software product that includes a tint block printing function.